dear list, i have a matrix with missing values like 1 2 3 4 x x 2 2 2 2 2 2 2 x 2 the x stands for the missing value. i have to substitute it to NA substitute or replace didn´t work out, as they are for vectors only however matrix[,i] also didn´t work. can anybody tell me, who i can change these values easily? thanks stefan [[alternative HTML version deleted]]
X <- matrix(c( 1, 2, 3, 4, "x",
"x", 2, 2, 2, 2,
2, 2, 2, "x", 2),
ncol=5, byrow=TRUE)
X.new <- matrix(as.numeric(X), ncol=ncol(X))
or
X.new <- apply(X, 2, function(x){replace(x, x == "x", NA)})
Stefan Semmeling wrote:> dear list,
>
> i have a matrix with missing values like
>
> 1 2 3 4 x
> x 2 2 2 2
> 2 2 2 x 2
>
> the x stands for the missing value.
> i have to substitute it to NA
>
> substitute or replace didn?t work out, as they are for vectors only
>
> however matrix[,i] also didn?t work.
>
> can anybody tell me, who i can change these values easily?
>
> thanks stefan
>
> [[alternative HTML version deleted]]
>
>
>
> ------------------------------------------------------------------------
>
> ______________________________________________
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--
Chuck Cleland, Ph.D.
NDRI, Inc.
71 West 23rd Street, 8th floor
New York, NY 10010
tel: (212) 845-4495 (Tu, Th)
tel: (732) 452-1424 (M, W, F)
fax: (917) 438-0894
One way: A <- matrix(round(rnorm(20)), ncol=4) A[2,1] <- "x" A[which(A == "x", arr.ind=TRUE)] <- NA A <- matrix(as.numeric(A), ncol=dim(A)[2]) Best, Matthias> -----Urspr?ngliche Nachricht----- > Von: r-help-bounces at stat.math.ethz.ch > [mailto:r-help-bounces at stat.math.ethz.ch] Im Auftrag von > Stefan Semmeling > Gesendet: Donnerstag, 09. M?rz 2006 14:32 > An: r-help at stat.math.ethz.ch > Betreff: [R] substituting values > Vertraulichkeit: Pers?nlich > > > dear list, > > i have a matrix with missing values like > > 1 2 3 4 x > x 2 2 2 2 > 2 2 2 x 2 > > the x stands for the missing value. > i have to substitute it to NA > > substitute or replace didn?t work out, as they are for vectors only > > however matrix[,i] also didn?t work. > > can anybody tell me, who i can change these values easily? > > thanks stefan > > [[alternative HTML version deleted]] > >
On Thu, Mar 09, 2006 at 08:44:27AM -0500, Chuck Cleland wrote:
<Chuck>X <- matrix(c( 1, 2, 3, 4, "x",
<Chuck> "x", 2, 2, 2, 2,
<Chuck> 2, 2, 2, "x", 2),
<Chuck> ncol=5, byrow=TRUE)
Why not:
X[X=="x"] <- NA
mode(X) <- "numeric" ## to get a numeric matrix
Btw if you got X with read.table you can specify the missing string.
?read.table
Ste
<Chuck>
<Chuck>X.new <- matrix(as.numeric(X), ncol=ncol(X))
<Chuck>
<Chuck>or
<Chuck>
<Chuck>X.new <- apply(X, 2, function(x){replace(x, x == "x",
NA)})
<Chuck>
<Chuck>Stefan Semmeling wrote:
<Chuck>> dear list,
<Chuck>>
<Chuck>> i have a matrix with missing values like
<Chuck>>
<Chuck>> 1 2 3 4 x
<Chuck>> x 2 2 2 2
<Chuck>> 2 2 2 x 2
<Chuck>>
<Chuck>> the x stands for the missing value.
<Chuck>> i have to substitute it to NA
<Chuck>>
<Chuck>> substitute or replace didn?t work out, as they are for vectors
only
<Chuck>>
<Chuck>> however matrix[,i] also didn?t work.
<Chuck>>
<Chuck>> can anybody tell me, who i can change these values easily?
<Chuck>>
<Chuck>> thanks stefan
<Chuck>>
<Chuck>> [[alternative HTML version deleted]]
<Chuck>>
<Chuck>>
<Chuck>>
<Chuck>>
------------------------------------------------------------------------
<Chuck>>
<Chuck>> ______________________________________________
<Chuck>> R-help at stat.math.ethz.ch mailing list
<Chuck>> https://stat.ethz.ch/mailman/listinfo/r-help
<Chuck>> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
<Chuck>
<Chuck>--
<Chuck>Chuck Cleland, Ph.D.
<Chuck>NDRI, Inc.
<Chuck>71 West 23rd Street, 8th floor
<Chuck>New York, NY 10010
<Chuck>tel: (212) 845-4495 (Tu, Th)
<Chuck>tel: (732) 452-1424 (M, W, F)
<Chuck>fax: (917) 438-0894
<Chuck>
<Chuck>______________________________________________
<Chuck>R-help at stat.math.ethz.ch mailing list
<Chuck>https://stat.ethz.ch/mailman/listinfo/r-help
<Chuck>PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html